The quiz is simple and to the point, with no cruft, so the overall experience is pretty good.
But I have a (slightly tangential) UX/design question: if now you are compelled to remove the Next button from the question pages, how would you achieve it, without reduction of functionality?
For example, on the first question, which is a single-choice question, if you make it submit on-click, then the user would lose the ability to change their mind before submitting, which is reduction of functionality. So maybe you'd consider doing a swipe-to-submit (punishing mouse users).
Then you have multiple-choice questions. Has anyone seen something clever that is both intuitive and removes the need for extra travel to the next button?
But if you really insist, then do what @yreg says, but include big, BIG back button at the top. Bonus points if you can make it look like stacked papers on the desktop:
NB Next button should be present always, even if it would be meaningless because you would advance on a single-choice question automatically. Thing is, sometimes things break and then someone would need to press the Next button.
Also you can use colour coding for multiple-choice questions by highlighting the Next button if anything selected, confirming for the user what they can advance.
And no, grey on white is the worst possible colour scheme ever.
We recently removed the next button from some of our customer flows because we had a lot of users repeatedly clicking on the option they selected instead of clicking the giant next button right below the options that even had animations after you selected an option.
We just gave them a back button if they make a mistake, which they rarely do.
I have iterated a fair bit of quizzing and surveying experiences.
Fewer clicks or taps always win, especially in the single radio button option scenarios. Visitors seem to appreciate that kind of seamless help as long as they can go back and forth if needed.
One simple approach for multiple-answer questions is to branch the additional resulting questions into the same queue to generate more than one scenario. There is a fair bit of tech out there to handle such decision making pretty easily.
Click to submit for single choice questions and keep next button for multi choice. Perhaps add checkboxes / radios so it's more clear which one is which.
But I have a (slightly tangential) UX/design question: if now you are compelled to remove the Next button from the question pages, how would you achieve it, without reduction of functionality?
For example, on the first question, which is a single-choice question, if you make it submit on-click, then the user would lose the ability to change their mind before submitting, which is reduction of functionality. So maybe you'd consider doing a swipe-to-submit (punishing mouse users).
Then you have multiple-choice questions. Has anyone seen something clever that is both intuitive and removes the need for extra travel to the next button?